1. Field of the Invention
The present invention relates to a combined chip/heat-dissipating metal plate. In particular, the present invention relates to a combined chip/heat-dissipating metal plate providing a heat-dissipating effect when the chip is cut by a laser cutting device. The present invention also relates to a method for manufacturing the chip/heat-dissipating metal plate.
2. Description of the Related Art
In current procedures for manufacturing light-emitting diodes (LEDs) and memories, numerous densely arrayed crystallite units are produced on a chip, and a laser cutting apparatus is used to cut the crystalline units into numerous crystallites. A typical chip includes an electrode layer, an epilayer (or epitaxy layer), and a gem layer. Before the laser cutting procedure, as show in FIG. 1, a chip 10 is adhered on a central area of an upper face of a see-through plastic film 12 placed on a working table of a laser cutting apparatus, with a metal supporting ring 13 adhered to a perimeter of the plastic film 12. An electronic microcamera is mounted above the working table for observing the arrangement and location of each crystallite unit in the epilayer of the chip 10. The chip is cut by a laser beam from top to obtain individual crystallites.
To improve the heat-dissipating effect for a chip for high-performance, high-brightness LEDs or high-frequency memories, it is well known to adhere a heat-dissipating metal plate 11 to a side of the chip 10, as shown in FIG. 2. A plurality of tiny balls are provided on the side of the chip 10 or adhesive is applied to the side of the chip 10. Next, the chip 10 and the heat-dissipating metal plate 11 are bonded together by applying pressure and heat.
The chip 10 is made of gallium nitride, gallium arsenide, or silicon and has a thickness smaller than 0.1 mm. Such a chip has high compression strength and poor tension strength in the radial direction. The heat-dissipating metal plate 11 is made of copper or aluminum and has a thickness smaller than 0.15 mm. When the heat-dissipating metal plate 11 is stretched, the thickness reduces. However, the heat-dissipating metal plate 11 has poor compression strength in the radial direction. When the combined chip/heat-dissipating metal plate is subjected to a tensile force, the chip 10 is damaged, although the heat-dissipating metal plate 11 may withstand the tensile force. The combined chip/heat-dissipating metal plate is unstable and thus may adversely affect the subsequent cutting.